Expansion type anchor bolts are known for many uses that require a bolt to be held strongly within a particular surface. A frequent use of anchor bolts is to secure a member, such as a wood panel, to a surface, such as concrete or cinderblock. Typical anchor bolts require a larger hole in the surface than in the panel. This can be inconvenient for the installer since the surface cannot be drilled with the panel in place. These problems are discussed in Whelan, Jr. U.S. Pat. No. 4,478,542, issued in 1984 and entitled EXPANSION ANCHOR GRIP SLEEVE. Whelan discloses a grip sleeve surrounding the bolt in the panel hole so that the panel hole may be of the same diameter as the underlying hole in the surface. The grip sleeve functions as a hole spacer and also restrains the anchor element from rotating during installation so that it can be expanded by insertion of the bolt to grip the hole in the surface.
A need for expansion type anchor studs, in other words devices that can be anchored in a surface with a threaded stud protruding therefrom for receiving a nut, also exists, and is constrained by analogous hole size problems such as have been discussed above.
Nicewarner et. al. U.S. Pat. No. 1,513,669, issued and entitled EXPANSIBLE BOLT, discloses a device especially adapted for use in structural iron work as a substitute for rivets, that comprises a hollow, slotted cylindrical member which is threaded at one end, ar expander in the form of a tapered pin extending through the cylindrical member and terminating in a threaded portion extending past the threaded end of the cylindrical member, and a a nut engaging the threaded end of the expander to expand the cylindrical member. A nut threaded over the threaded end of the cylindrical member and a head at the opposite end of the cylindrical member act in concert to clamp two pieces of structural iron, both having holes therethrough, together. Nicewarner inherently addresses the "same hole size in both members" problem, since it is a rivet which is inserted from one side of the two ultimately fastened together members and which is tightened from the other side thereof. However, Nicewarner does not address the problems associated with anchor bolts and anchor studs, as discussed above, since both anchor blots and anchor studs are required to be used in "blind" hole applications. In other words, the hole in the surface does not extend all the way therethrough.